Ethyl orthoformate → 4-Chloro-7-cyclobutyl-7H-imidazo[4,5-c]pyridazine

Reaction equation

[Cl:1][C:2]1[C:3]([NH2:13])=[C:4]([NH:8][CH:9]2[CH2:12][CH2:11][CH2:10]2)[N:5]=[N:6][CH:7]=1.[CH:14](OCC)(OCC)OCC>>[Cl:1][C:2]1[C:3]2[N:13]=[CH:14][N:8]([CH:9]3[CH2:12][CH2:11][CH2:10]3)[C:4]=2[N:5]=[N:6][CH:7]=1

Participants

Reactant 2

HCID 31214Ethyl orthoformate

HCID 867232805-Chloro-N3-cyclobutylpyridazine-3,4-diamine

Product 1

HCID 867232814-Chloro-7-cyclobutyl-7H-imidazo[4,5-c]pyridazineYield 54%

Conditions

Temperature: 140 °C

Procedure

A mixture of 5-chloro-N3-cyclobutylpyridazin-3,4-diamine (Preparation 98, 140 mg, 0.70 mmol) and triethyl orthoformate (4 mL) was heated at 140° C. for 4 hours. After evaporation in vacuo, the crude residue was purified by silica gel column chromatography eluting with CH2Cl2:MeOH 99:1 to afford the title compound as an off white solid in 54% yield, 80 mg.

Workup

customAfter evaporation in vacuo
customthe crude residue was purified by silica gel column chromatography
washeluting with CH2Cl2:MeOH 99:1

Sources & evidence

ORD record: ord-dc641c0ae8d04a488de35a4efb4d0fcc
Source dataset: uspto-grants-2015_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08952008B2

Reaction notes

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